Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1683 insertions, 0 deletions

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
new file mode 100644
index 000000000..ca5a6c3f8
--- /dev/null
+++ b/arch/x86/kvm/hyperv.c
@@ -0,0 +1,1683 @@
+/*
+ * KVM Microsoft Hyper-V emulation
+ *
+ * derived from arch/x86/kvm/x86.c
+ *
+ * Copyright (C) 2006 Qumranet, Inc.
+ * Copyright (C) 2008 Qumranet, Inc.
+ * Copyright IBM Corporation, 2008
+ * Copyright 2010 Red Hat, Inc. and/or its affiliates.
+ * Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
+ *
+ * Authors:
+ *   Avi Kivity   <avi@qumranet.com>
+ *   Yaniv Kamay  <yaniv@qumranet.com>
+ *   Amit Shah    <amit.shah@qumranet.com>
+ *   Ben-Ami Yassour <benami@il.ibm.com>
+ *   Andrey Smetanin <asmetanin@virtuozzo.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "x86.h"
+#include "lapic.h"
+#include "ioapic.h"
+#include "hyperv.h"
+
+#include <linux/kvm_host.h>
+#include <linux/highmem.h>
+#include <linux/sched/cputime.h>
+#include <linux/eventfd.h>
+
+#include <asm/apicdef.h>
+#include <trace/events/kvm.h>
+
+#include "trace.h"
+
+static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
+{
+	return atomic64_read(&synic->sint[sint]);
+}
+
+static inline int synic_get_sint_vector(u64 sint_value)
+{
+	if (sint_value & HV_SYNIC_SINT_MASKED)
+		return -1;
+	return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
+}
+
+static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
+				      int vector)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
+		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
+			return true;
+	}
+	return false;
+}
+
+static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
+				     int vector)
+{
+	int i;
+	u64 sint_value;
+
+	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
+		sint_value = synic_read_sint(synic, i);
+		if (synic_get_sint_vector(sint_value) == vector &&
+		    sint_value & HV_SYNIC_SINT_AUTO_EOI)
+			return true;
+	}
+	return false;
+}
+
+static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
+				int vector)
+{
+	if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
+		return;
+
+	if (synic_has_vector_connected(synic, vector))
+		__set_bit(vector, synic->vec_bitmap);
+	else
+		__clear_bit(vector, synic->vec_bitmap);
+
+	if (synic_has_vector_auto_eoi(synic, vector))
+		__set_bit(vector, synic->auto_eoi_bitmap);
+	else
+		__clear_bit(vector, synic->auto_eoi_bitmap);
+}
+
+static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
+			  u64 data, bool host)
+{
+	int vector, old_vector;
+	bool masked;
+
+	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
+	masked = data & HV_SYNIC_SINT_MASKED;
+
+	/*
+	 * Valid vectors are 16-255, however, nested Hyper-V attempts to write
+	 * default '0x10000' value on boot and this should not #GP. We need to
+	 * allow zero-initing the register from host as well.
+	 */
+	if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
+		return 1;
+	/*
+	 * Guest may configure multiple SINTs to use the same vector, so
+	 * we maintain a bitmap of vectors handled by synic, and a
+	 * bitmap of vectors with auto-eoi behavior.  The bitmaps are
+	 * updated here, and atomically queried on fast paths.
+	 */
+	old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
+
+	atomic64_set(&synic->sint[sint], data);
+
+	synic_update_vector(synic, old_vector);
+
+	synic_update_vector(synic, vector);
+
+	/* Load SynIC vectors into EOI exit bitmap */
+	kvm_make_request(KVM_REQ_SCAN_IOAPIC, synic_to_vcpu(synic));
+	return 0;
+}
+
+static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
+{
+	struct kvm_vcpu *vcpu = NULL;
+	int i;
+
+	if (vpidx >= KVM_MAX_VCPUS)
+		return NULL;
+
+	vcpu = kvm_get_vcpu(kvm, vpidx);
+	if (vcpu && vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
+		return vcpu;
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		if (vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
+			return vcpu;
+	return NULL;
+}
+
+static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vcpu_hv_synic *synic;
+
+	vcpu = get_vcpu_by_vpidx(kvm, vpidx);
+	if (!vcpu)
+		return NULL;
+	synic = vcpu_to_synic(vcpu);
+	return (synic->active) ? synic : NULL;
+}
+
+static void synic_clear_sint_msg_pending(struct kvm_vcpu_hv_synic *synic,
+					u32 sint)
+{
+	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
+	struct page *page;
+	gpa_t gpa;
+	struct hv_message *msg;
+	struct hv_message_page *msg_page;
+
+	gpa = synic->msg_page & PAGE_MASK;
+	page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
+	if (is_error_page(page)) {
+		vcpu_err(vcpu, "Hyper-V SynIC can't get msg page, gpa 0x%llx\n",
+			 gpa);
+		return;
+	}
+	msg_page = kmap_atomic(page);
+
+	msg = &msg_page->sint_message[sint];
+	msg->header.message_flags.msg_pending = 0;
+
+	kunmap_atomic(msg_page);
+	kvm_release_page_dirty(page);
+	kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
+}
+
+static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
+	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
+	struct kvm_vcpu_hv_stimer *stimer;
+	int gsi, idx, stimers_pending;
+
+	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
+
+	if (synic->msg_page & HV_SYNIC_SIMP_ENABLE)
+		synic_clear_sint_msg_pending(synic, sint);
+
+	/* Try to deliver pending Hyper-V SynIC timers messages */
+	stimers_pending = 0;
+	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
+		stimer = &hv_vcpu->stimer[idx];
+		if (stimer->msg_pending &&
+		    (stimer->config & HV_STIMER_ENABLE) &&
+		    HV_STIMER_SINT(stimer->config) == sint) {
+			set_bit(stimer->index,
+				hv_vcpu->stimer_pending_bitmap);
+			stimers_pending++;
+		}
+	}
+	if (stimers_pending)
+		kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
+
+	idx = srcu_read_lock(&kvm->irq_srcu);
+	gsi = atomic_read(&synic->sint_to_gsi[sint]);
+	if (gsi != -1)
+		kvm_notify_acked_gsi(kvm, gsi);
+	srcu_read_unlock(&kvm->irq_srcu, idx);
+}
+
+static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
+{
+	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
+	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
+
+	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
+	hv_vcpu->exit.u.synic.msr = msr;
+	hv_vcpu->exit.u.synic.control = synic->control;
+	hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
+	hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
+
+	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
+}
+
+static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
+			 u32 msr, u64 data, bool host)
+{
+	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
+	int ret;
+
+	if (!synic->active && (!host || data))
+		return 1;
+
+	trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
+
+	ret = 0;
+	switch (msr) {
+	case HV_X64_MSR_SCONTROL:
+		synic->control = data;
+		if (!host)
+			synic_exit(synic, msr);
+		break;
+	case HV_X64_MSR_SVERSION:
+		if (!host) {
+			ret = 1;
+			break;
+		}
+		synic->version = data;
+		break;
+	case HV_X64_MSR_SIEFP:
+		if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
+		    !synic->dont_zero_synic_pages)
+			if (kvm_clear_guest(vcpu->kvm,
+					    data & PAGE_MASK, PAGE_SIZE)) {
+				ret = 1;
+				break;
+			}
+		synic->evt_page = data;
+		if (!host)
+			synic_exit(synic, msr);
+		break;
+	case HV_X64_MSR_SIMP:
+		if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
+		    !synic->dont_zero_synic_pages)
+			if (kvm_clear_guest(vcpu->kvm,
+					    data & PAGE_MASK, PAGE_SIZE)) {
+				ret = 1;
+				break;
+			}
+		synic->msg_page = data;
+		if (!host)
+			synic_exit(synic, msr);
+		break;
+	case HV_X64_MSR_EOM: {
+		int i;
+
+		if (!synic->active)
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
+			kvm_hv_notify_acked_sint(vcpu, i);
+		break;
+	}
+	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
+		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
+		break;
+	default:
+		ret = 1;
+		break;
+	}
+	return ret;
+}
+
+static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
+			 bool host)
+{
+	int ret;
+
+	if (!synic->active && !host)
+		return 1;
+
+	ret = 0;
+	switch (msr) {
+	case HV_X64_MSR_SCONTROL:
+		*pdata = synic->control;
+		break;
+	case HV_X64_MSR_SVERSION:
+		*pdata = synic->version;
+		break;
+	case HV_X64_MSR_SIEFP:
+		*pdata = synic->evt_page;
+		break;
+	case HV_X64_MSR_SIMP:
+		*pdata = synic->msg_page;
+		break;
+	case HV_X64_MSR_EOM:
+		*pdata = 0;
+		break;
+	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
+		*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
+		break;
+	default:
+		ret = 1;
+		break;
+	}
+	return ret;
+}
+
+static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
+{
+	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
+	struct kvm_lapic_irq irq;
+	int ret, vector;
+
+	if (sint >= ARRAY_SIZE(synic->sint))
+		return -EINVAL;
+
+	vector = synic_get_sint_vector(synic_read_sint(synic, sint));
+	if (vector < 0)
+		return -ENOENT;
+
+	memset(&irq, 0, sizeof(irq));
+	irq.shorthand = APIC_DEST_SELF;
+	irq.dest_mode = APIC_DEST_PHYSICAL;
+	irq.delivery_mode = APIC_DM_FIXED;
+	irq.vector = vector;
+	irq.level = 1;
+
+	ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
+	trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
+	return ret;
+}
+
+int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
+{
+	struct kvm_vcpu_hv_synic *synic;
+
+	synic = synic_get(kvm, vpidx);
+	if (!synic)
+		return -EINVAL;
+
+	return synic_set_irq(synic, sint);
+}
+
+void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
+{
+	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
+	int i;
+
+	trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
+
+	for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
+		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
+			kvm_hv_notify_acked_sint(vcpu, i);
+}
+
+static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
+{
+	struct kvm_vcpu_hv_synic *synic;
+
+	synic = synic_get(kvm, vpidx);
+	if (!synic)
+		return -EINVAL;
+
+	if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
+		return -EINVAL;
+
+	atomic_set(&synic->sint_to_gsi[sint], gsi);
+	return 0;
+}
+
+void kvm_hv_irq_routing_update(struct kvm *kvm)
+{
+	struct kvm_irq_routing_table *irq_rt;
+	struct kvm_kernel_irq_routing_entry *e;
+	u32 gsi;
+
+	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
+					lockdep_is_held(&kvm->irq_lock));
+
+	for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
+		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
+			if (e->type == KVM_IRQ_ROUTING_HV_SINT)
+				kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
+						    e->hv_sint.sint, gsi);
+		}
+	}
+}
+
+static void synic_init(struct kvm_vcpu_hv_synic *synic)
+{
+	int i;
+
+	memset(synic, 0, sizeof(*synic));
+	synic->version = HV_SYNIC_VERSION_1;
+	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
+		atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
+		atomic_set(&synic->sint_to_gsi[i], -1);
+	}
+}
+
+static u64 get_time_ref_counter(struct kvm *kvm)
+{
+	struct kvm_hv *hv = &kvm->arch.hyperv;
+	struct kvm_vcpu *vcpu;
+	u64 tsc;
+
+	/*
+	 * The guest has not set up the TSC page or the clock isn't
+	 * stable, fall back to get_kvmclock_ns.
+	 */
+	if (!hv->tsc_ref.tsc_sequence)
+		return div_u64(get_kvmclock_ns(kvm), 100);
+
+	vcpu = kvm_get_vcpu(kvm, 0);
+	tsc = kvm_read_l1_tsc(vcpu, rdtsc());
+	return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
+		+ hv->tsc_ref.tsc_offset;
+}
+
+static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
+				bool vcpu_kick)
+{
+	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
+
+	set_bit(stimer->index,
+		vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
+	kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
+	if (vcpu_kick)
+		kvm_vcpu_kick(vcpu);
+}
+
+static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
+{
+	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
+
+	trace_kvm_hv_stimer_cleanup(stimer_to_vcpu(stimer)->vcpu_id,
+				    stimer->index);
+
+	hrtimer_cancel(&stimer->timer);
+	clear_bit(stimer->index,
+		  vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
+	stimer->msg_pending = false;
+	stimer->exp_time = 0;
+}
+
+static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
+{
+	struct kvm_vcpu_hv_stimer *stimer;
+
+	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
+	trace_kvm_hv_stimer_callback(stimer_to_vcpu(stimer)->vcpu_id,
+				     stimer->index);
+	stimer_mark_pending(stimer, true);
+
+	return HRTIMER_NORESTART;
+}
+
+/*
+ * stimer_start() assumptions:
+ * a) stimer->count is not equal to 0
+ * b) stimer->config has HV_STIMER_ENABLE flag
+ */
+static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
+{
+	u64 time_now;
+	ktime_t ktime_now;
+
+	time_now = get_time_ref_counter(stimer_to_vcpu(stimer)->kvm);
+	ktime_now = ktime_get();
+
+	if (stimer->config & HV_STIMER_PERIODIC) {
+		if (stimer->exp_time) {
+			if (time_now >= stimer->exp_time) {
+				u64 remainder;
+
+				div64_u64_rem(time_now - stimer->exp_time,
+					      stimer->count, &remainder);
+				stimer->exp_time =
+					time_now + (stimer->count - remainder);
+			}
+		} else
+			stimer->exp_time = time_now + stimer->count;
+
+		trace_kvm_hv_stimer_start_periodic(
+					stimer_to_vcpu(stimer)->vcpu_id,
+					stimer->index,
+					time_now, stimer->exp_time);
+
+		hrtimer_start(&stimer->timer,
+			      ktime_add_ns(ktime_now,
+					   100 * (stimer->exp_time - time_now)),
+			      HRTIMER_MODE_ABS);
+		return 0;
+	}
+	stimer->exp_time = stimer->count;
+	if (time_now >= stimer->count) {
+		/*
+		 * Expire timer according to Hypervisor Top-Level Functional
+		 * specification v4(15.3.1):
+		 * "If a one shot is enabled and the specified count is in
+		 * the past, it will expire immediately."
+		 */
+		stimer_mark_pending(stimer, false);
+		return 0;
+	}
+
+	trace_kvm_hv_stimer_start_one_shot(stimer_to_vcpu(stimer)->vcpu_id,
+					   stimer->index,
+					   time_now, stimer->count);
+
+	hrtimer_start(&stimer->timer,
+		      ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
+		      HRTIMER_MODE_ABS);
+	return 0;
+}
+
+static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
+			     bool host)
+{
+	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
+	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
+
+	if (!synic->active && (!host || config))
+		return 1;
+
+	trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id,
+				       stimer->index, config, host);
+
+	stimer_cleanup(stimer);
+	if ((stimer->config & HV_STIMER_ENABLE) && HV_STIMER_SINT(config) == 0)
+		config &= ~HV_STIMER_ENABLE;
+	stimer->config = config;
+	stimer_mark_pending(stimer, false);
+	return 0;
+}
+
+static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
+			    bool host)
+{
+	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
+	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
+
+	if (!synic->active && (!host || count))
+		return 1;
+
+	trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id,
+				      stimer->index, count, host);
+
+	stimer_cleanup(stimer);
+	stimer->count = count;
+	if (stimer->count == 0)
+		stimer->config &= ~HV_STIMER_ENABLE;
+	else if (stimer->config & HV_STIMER_AUTOENABLE)
+		stimer->config |= HV_STIMER_ENABLE;
+	stimer_mark_pending(stimer, false);
+	return 0;
+}
+
+static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
+{
+	*pconfig = stimer->config;
+	return 0;
+}
+
+static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
+{
+	*pcount = stimer->count;
+	return 0;
+}
+
+static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
+			     struct hv_message *src_msg)
+{
+	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
+	struct page *page;
+	gpa_t gpa;
+	struct hv_message *dst_msg;
+	int r;
+	struct hv_message_page *msg_page;
+
+	if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
+		return -ENOENT;
+
+	gpa = synic->msg_page & PAGE_MASK;
+	page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
+	if (is_error_page(page))
+		return -EFAULT;
+
+	msg_page = kmap_atomic(page);
+	dst_msg = &msg_page->sint_message[sint];
+	if (sync_cmpxchg(&dst_msg->header.message_type, HVMSG_NONE,
+			 src_msg->header.message_type) != HVMSG_NONE) {
+		dst_msg->header.message_flags.msg_pending = 1;
+		r = -EAGAIN;
+	} else {
+		memcpy(&dst_msg->u.payload, &src_msg->u.payload,
+		       src_msg->header.payload_size);
+		dst_msg->header.message_type = src_msg->header.message_type;
+		dst_msg->header.payload_size = src_msg->header.payload_size;
+		r = synic_set_irq(synic, sint);
+		if (r >= 1)
+			r = 0;
+		else if (r == 0)
+			r = -EFAULT;
+	}
+	kunmap_atomic(msg_page);
+	kvm_release_page_dirty(page);
+	kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
+	return r;
+}
+
+static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
+{
+	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
+	struct hv_message *msg = &stimer->msg;
+	struct hv_timer_message_payload *payload =
+			(struct hv_timer_message_payload *)&msg->u.payload;
+
+	payload->expiration_time = stimer->exp_time;
+	payload->delivery_time = get_time_ref_counter(vcpu->kvm);
+	return synic_deliver_msg(vcpu_to_synic(vcpu),
+				 HV_STIMER_SINT(stimer->config), msg);
+}
+
+static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
+{
+	int r;
+
+	stimer->msg_pending = true;
+	r = stimer_send_msg(stimer);
+	trace_kvm_hv_stimer_expiration(stimer_to_vcpu(stimer)->vcpu_id,
+				       stimer->index, r);
+	if (!r) {
+		stimer->msg_pending = false;
+		if (!(stimer->config & HV_STIMER_PERIODIC))
+			stimer->config &= ~HV_STIMER_ENABLE;
+	}
+}
+
+void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
+	struct kvm_vcpu_hv_stimer *stimer;
+	u64 time_now, exp_time;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
+		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
+			stimer = &hv_vcpu->stimer[i];
+			if (stimer->config & HV_STIMER_ENABLE) {
+				exp_time = stimer->exp_time;
+
+				if (exp_time) {
+					time_now =
+						get_time_ref_counter(vcpu->kvm);
+					if (time_now >= exp_time)
+						stimer_expiration(stimer);
+				}
+
+				if ((stimer->config & HV_STIMER_ENABLE) &&
+				    stimer->count) {
+					if (!stimer->msg_pending)
+						stimer_start(stimer);
+				} else
+					stimer_cleanup(stimer);
+			}
+		}
+}
+
+void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
+		stimer_cleanup(&hv_vcpu->stimer[i]);
+}
+
+bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
+{
+	if (!(vcpu->arch.hyperv.hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
+		return false;
+	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
+}
+EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
+
+bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
+			    struct hv_vp_assist_page *assist_page)
+{
+	if (!kvm_hv_assist_page_enabled(vcpu))
+		return false;
+	return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
+				      assist_page, sizeof(*assist_page));
+}
+EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
+
+static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
+{
+	struct hv_message *msg = &stimer->msg;
+	struct hv_timer_message_payload *payload =
+			(struct hv_timer_message_payload *)&msg->u.payload;
+
+	memset(&msg->header, 0, sizeof(msg->header));
+	msg->header.message_type = HVMSG_TIMER_EXPIRED;
+	msg->header.payload_size = sizeof(*payload);
+
+	payload->timer_index = stimer->index;
+	payload->expiration_time = 0;
+	payload->delivery_time = 0;
+}
+
+static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
+{
+	memset(stimer, 0, sizeof(*stimer));
+	stimer->index = timer_index;
+	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	stimer->timer.function = stimer_timer_callback;
+	stimer_prepare_msg(stimer);
+}
+
+void kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
+	int i;
+
+	synic_init(&hv_vcpu->synic);
+
+	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
+	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
+		stimer_init(&hv_vcpu->stimer[i], i);
+}
+
+void kvm_hv_vcpu_postcreate(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
+
+	hv_vcpu->vp_index = kvm_vcpu_get_idx(vcpu);
+}
+
+int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
+{
+	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
+
+	/*
+	 * Hyper-V SynIC auto EOI SINT's are
+	 * not compatible with APICV, so deactivate APICV
+	 */
+	kvm_vcpu_deactivate_apicv(vcpu);
+	synic->active = true;
+	synic->dont_zero_synic_pages = dont_zero_synic_pages;
+	return 0;
+}
+
+static bool kvm_hv_msr_partition_wide(u32 msr)
+{
+	bool r = false;
+
+	switch (msr) {
+	case HV_X64_MSR_GUEST_OS_ID:
+	case HV_X64_MSR_HYPERCALL:
+	case HV_X64_MSR_REFERENCE_TSC:
+	case HV_X64_MSR_TIME_REF_COUNT:
+	case HV_X64_MSR_CRASH_CTL:
+	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
+	case HV_X64_MSR_RESET:
+	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
+	case HV_X64_MSR_TSC_EMULATION_CONTROL:
+	case HV_X64_MSR_TSC_EMULATION_STATUS:
+		r = true;
+		break;
+	}
+
+	return r;
+}
+
+static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu,
+				     u32 index, u64 *pdata)
+{
+	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
+	size_t size = ARRAY_SIZE(hv->hv_crash_param);
+
+	if (WARN_ON_ONCE(index >= size))
+		return -EINVAL;
+
+	*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
+	return 0;
+}
+
+static int kvm_hv_msr_get_crash_ctl(struct kvm_vcpu *vcpu, u64 *pdata)
+{
+	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
+
+	*pdata = hv->hv_crash_ctl;
+	return 0;
+}
+
+static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data, bool host)
+{
+	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
+
+	if (host)
+		hv->hv_crash_ctl = data & HV_X64_MSR_CRASH_CTL_NOTIFY;
+
+	if (!host && (data & HV_X64_MSR_CRASH_CTL_NOTIFY)) {
+
+		vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
+			  hv->hv_crash_param[0],
+			  hv->hv_crash_param[1],
+			  hv->hv_crash_param[2],
+			  hv->hv_crash_param[3],
+			  hv->hv_crash_param[4]);
+
+		/* Send notification about crash to user space */
+		kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
+	}
+
+	return 0;
+}
+
+static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu,
+				     u32 index, u64 data)
+{
+	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
+	size_t size = ARRAY_SIZE(hv->hv_crash_param);
+
+	if (WARN_ON_ONCE(index >= size))
+		return -EINVAL;
+
+	hv->hv_crash_param[array_index_nospec(index, size)] = data;
+	return 0;
+}
+
+/*
+ * The kvmclock and Hyper-V TSC page use similar formulas, and converting
+ * between them is possible:
+ *
+ * kvmclock formula:
+ *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
+ *           + system_time
+ *
+ * Hyper-V formula:
+ *    nsec/100 = ticks * scale / 2^64 + offset
+ *
+ * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
+ * By dividing the kvmclock formula by 100 and equating what's left we get:
+ *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
+ *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
+ *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
+ *
+ * Now expand the kvmclock formula and divide by 100:
+ *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
+ *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
+ *           + system_time
+ *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
+ *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
+ *               + system_time / 100
+ *
+ * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
+ *    nsec/100 = ticks * scale / 2^64
+ *               - tsc_timestamp * scale / 2^64
+ *               + system_time / 100
+ *
+ * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
+ *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
+ *
+ * These two equivalencies are implemented in this function.
+ */
+static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
+					HV_REFERENCE_TSC_PAGE *tsc_ref)
+{
+	u64 max_mul;
+
+	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
+		return false;
+
+	/*
+	 * check if scale would overflow, if so we use the time ref counter
+	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
+	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
+	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
+	 */
+	max_mul = 100ull << (32 - hv_clock->tsc_shift);
+	if (hv_clock->tsc_to_system_mul >= max_mul)
+		return false;
+
+	/*
+	 * Otherwise compute the scale and offset according to the formulas
+	 * derived above.
+	 */
+	tsc_ref->tsc_scale =
+		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
+				hv_clock->tsc_to_system_mul,
+				100);
+
+	tsc_ref->tsc_offset = hv_clock->system_time;
+	do_div(tsc_ref->tsc_offset, 100);
+	tsc_ref->tsc_offset -=
+		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
+	return true;
+}
+
+void kvm_hv_setup_tsc_page(struct kvm *kvm,
+			   struct pvclock_vcpu_time_info *hv_clock)
+{
+	struct kvm_hv *hv = &kvm->arch.hyperv;
+	u32 tsc_seq;
+	u64 gfn;
+
+	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
+	BUILD_BUG_ON(offsetof(HV_REFERENCE_TSC_PAGE, tsc_sequence) != 0);
+
+	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
+		return;
+
+	mutex_lock(&kvm->arch.hyperv.hv_lock);
+	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
+		goto out_unlock;
+
+	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
+	/*
+	 * Because the TSC parameters only vary when there is a
+	 * change in the master clock, do not bother with caching.
+	 */
+	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
+				    &tsc_seq, sizeof(tsc_seq))))
+		goto out_unlock;
+
+	/*
+	 * While we're computing and writing the parameters, force the
+	 * guest to use the time reference count MSR.
+	 */
+	hv->tsc_ref.tsc_sequence = 0;
+	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
+			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
+		goto out_unlock;
+
+	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
+		goto out_unlock;
+
+	/* Ensure sequence is zero before writing the rest of the struct.  */
+	smp_wmb();
+	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
+		goto out_unlock;
+
+	/*
+	 * Now switch to the TSC page mechanism by writing the sequence.
+	 */
+	tsc_seq++;
+	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
+		tsc_seq = 1;
+
+	/* Write the struct entirely before the non-zero sequence.  */
+	smp_wmb();
+
+	hv->tsc_ref.tsc_sequence = tsc_seq;
+	kvm_write_guest(kvm, gfn_to_gpa(gfn),
+			&hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence));
+out_unlock:
+	mutex_unlock(&kvm->arch.hyperv.hv_lock);
+}
+
+static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
+			     bool host)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_hv *hv = &kvm->arch.hyperv;
+
+	switch (msr) {
+	case HV_X64_MSR_GUEST_OS_ID:
+		hv->hv_guest_os_id = data;
+		/* setting guest os id to zero disables hypercall page */
+		if (!hv->hv_guest_os_id)
+			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
+		break;
+	case HV_X64_MSR_HYPERCALL: {
+		u64 gfn;
+		unsigned long addr;
+		u8 instructions[4];
+
+		/* if guest os id is not set hypercall should remain disabled */
+		if (!hv->hv_guest_os_id)
+			break;
+		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
+			hv->hv_hypercall = data;
+			break;
+		}
+		gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
+		addr = gfn_to_hva(kvm, gfn);
+		if (kvm_is_error_hva(addr))
+			return 1;
+		kvm_x86_ops->patch_hypercall(vcpu, instructions);
+		((unsigned char *)instructions)[3] = 0xc3; /* ret */
+		if (__copy_to_user((void __user *)addr, instructions, 4))
+			return 1;
+		hv->hv_hypercall = data;
+		mark_page_dirty(kvm, gfn);
+		break;
+	}
+	case HV_X64_MSR_REFERENCE_TSC:
+		hv->hv_tsc_page = data;
+		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)
+			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
+		break;
+	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
+		return kvm_hv_msr_set_crash_data(vcpu,
+						 msr - HV_X64_MSR_CRASH_P0,
+						 data);
+	case HV_X64_MSR_CRASH_CTL:
+		return kvm_hv_msr_set_crash_ctl(vcpu, data, host);
+	case HV_X64_MSR_RESET:
+		if (data == 1) {
+			vcpu_debug(vcpu, "hyper-v reset requested\n");
+			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
+		}
+		break;
+	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
+		hv->hv_reenlightenment_control = data;
+		break;
+	case HV_X64_MSR_TSC_EMULATION_CONTROL:
+		hv->hv_tsc_emulation_control = data;
+		break;
+	case HV_X64_MSR_TSC_EMULATION_STATUS:
+		hv->hv_tsc_emulation_status = data;
+		break;
+	case HV_X64_MSR_TIME_REF_COUNT:
+		/* read-only, but still ignore it if host-initiated */
+		if (!host)
+			return 1;
+		break;
+	default:
+		vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
+			    msr, data);
+		return 1;
+	}
+	return 0;
+}
+
+/* Calculate cpu time spent by current task in 100ns units */
+static u64 current_task_runtime_100ns(void)
+{
+	u64 utime, stime;
+
+	task_cputime_adjusted(current, &utime, &stime);
+
+	return div_u64(utime + stime, 100);
+}
+
+static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
+{
+	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
+
+	switch (msr) {
+	case HV_X64_MSR_VP_INDEX: {
+		struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
+		int vcpu_idx = kvm_vcpu_get_idx(vcpu);
+		u32 new_vp_index = (u32)data;
+
+		if (!host || new_vp_index >= KVM_MAX_VCPUS)
+			return 1;
+
+		if (new_vp_index == hv_vcpu->vp_index)
+			return 0;
+
+		/*
+		 * The VP index is initialized to vcpu_index by
+		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
+		 * VP index is changing, adjust num_mismatched_vp_indexes if
+		 * it now matches or no longer matches vcpu_idx.
+		 */
+		if (hv_vcpu->vp_index == vcpu_idx)
+			atomic_inc(&hv->num_mismatched_vp_indexes);
+		else if (new_vp_index == vcpu_idx)
+			atomic_dec(&hv->num_mismatched_vp_indexes);
+
+		hv_vcpu->vp_index = new_vp_index;
+		break;
+	}
+	case HV_X64_MSR_VP_ASSIST_PAGE: {
+		u64 gfn;
+		unsigned long addr;
+
+		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
+			hv_vcpu->hv_vapic = data;
+			if (kvm_lapic_enable_pv_eoi(vcpu, 0, 0))
+				return 1;
+			break;
+		}
+		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
+		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
+		if (kvm_is_error_hva(addr))
+			return 1;
+		if (__clear_user((void __user *)addr, PAGE_SIZE))
+			return 1;
+		hv_vcpu->hv_vapic = data;
+		kvm_vcpu_mark_page_dirty(vcpu, gfn);
+		if (kvm_lapic_enable_pv_eoi(vcpu,
+					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
+					    sizeof(struct hv_vp_assist_page)))
+			return 1;
+		break;
+	}
+	case HV_X64_MSR_EOI:
+		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
+	case HV_X64_MSR_ICR:
+		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
+	case HV_X64_MSR_TPR:
+		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
+	case HV_X64_MSR_VP_RUNTIME:
+		if (!host)
+			return 1;
+		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
+		break;
+	case HV_X64_MSR_SCONTROL:
+	case HV_X64_MSR_SVERSION:
+	case HV_X64_MSR_SIEFP:
+	case HV_X64_MSR_SIMP:
+	case HV_X64_MSR_EOM:
+	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
+		return synic_set_msr(vcpu_to_synic(vcpu), msr, data, host);
+	case HV_X64_MSR_STIMER0_CONFIG:
+	case HV_X64_MSR_STIMER1_CONFIG:
+	case HV_X64_MSR_STIMER2_CONFIG:
+	case HV_X64_MSR_STIMER3_CONFIG: {
+		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
+
+		return stimer_set_config(vcpu_to_stimer(vcpu, timer_index),
+					 data, host);
+	}
+	case HV_X64_MSR_STIMER0_COUNT:
+	case HV_X64_MSR_STIMER1_COUNT:
+	case HV_X64_MSR_STIMER2_COUNT:
+	case HV_X64_MSR_STIMER3_COUNT: {
+		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
+
+		return stimer_set_count(vcpu_to_stimer(vcpu, timer_index),
+					data, host);
+	}
+	case HV_X64_MSR_TSC_FREQUENCY:
+	case HV_X64_MSR_APIC_FREQUENCY:
+		/* read-only, but still ignore it if host-initiated */
+		if (!host)
+			return 1;
+		break;
+	default:
+		vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
+			    msr, data);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
+{
+	u64 data = 0;
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_hv *hv = &kvm->arch.hyperv;
+
+	switch (msr) {
+	case HV_X64_MSR_GUEST_OS_ID:
+		data = hv->hv_guest_os_id;
+		break;
+	case HV_X64_MSR_HYPERCALL:
+		data = hv->hv_hypercall;
+		break;
+	case HV_X64_MSR_TIME_REF_COUNT:
+		data = get_time_ref_counter(kvm);
+		break;
+	case HV_X64_MSR_REFERENCE_TSC:
+		data = hv->hv_tsc_page;
+		break;
+	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
+		return kvm_hv_msr_get_crash_data(vcpu,
+						 msr - HV_X64_MSR_CRASH_P0,
+						 pdata);
+	case HV_X64_MSR_CRASH_CTL:
+		return kvm_hv_msr_get_crash_ctl(vcpu, pdata);
+	case HV_X64_MSR_RESET:
+		data = 0;
+		break;
+	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
+		data = hv->hv_reenlightenment_control;
+		break;
+	case HV_X64_MSR_TSC_EMULATION_CONTROL:
+		data = hv->hv_tsc_emulation_control;
+		break;
+	case HV_X64_MSR_TSC_EMULATION_STATUS:
+		data = hv->hv_tsc_emulation_status;
+		break;
+	default:
+		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
+		return 1;
+	}
+
+	*pdata = data;
+	return 0;
+}
+
+static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
+			  bool host)
+{
+	u64 data = 0;
+	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
+
+	switch (msr) {
+	case HV_X64_MSR_VP_INDEX:
+		data = hv_vcpu->vp_index;
+		break;
+	case HV_X64_MSR_EOI:
+		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
+	case HV_X64_MSR_ICR:
+		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
+	case HV_X64_MSR_TPR:
+		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
+	case HV_X64_MSR_VP_ASSIST_PAGE:
+		data = hv_vcpu->hv_vapic;
+		break;
+	case HV_X64_MSR_VP_RUNTIME:
+		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
+		break;
+	case HV_X64_MSR_SCONTROL:
+	case HV_X64_MSR_SVERSION:
+	case HV_X64_MSR_SIEFP:
+	case HV_X64_MSR_SIMP:
+	case HV_X64_MSR_EOM:
+	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
+		return synic_get_msr(vcpu_to_synic(vcpu), msr, pdata, host);
+	case HV_X64_MSR_STIMER0_CONFIG:
+	case HV_X64_MSR_STIMER1_CONFIG:
+	case HV_X64_MSR_STIMER2_CONFIG:
+	case HV_X64_MSR_STIMER3_CONFIG: {
+		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
+
+		return stimer_get_config(vcpu_to_stimer(vcpu, timer_index),
+					 pdata);
+	}
+	case HV_X64_MSR_STIMER0_COUNT:
+	case HV_X64_MSR_STIMER1_COUNT:
+	case HV_X64_MSR_STIMER2_COUNT:
+	case HV_X64_MSR_STIMER3_COUNT: {
+		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
+
+		return stimer_get_count(vcpu_to_stimer(vcpu, timer_index),
+					pdata);
+	}
+	case HV_X64_MSR_TSC_FREQUENCY:
+		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
+		break;
+	case HV_X64_MSR_APIC_FREQUENCY:
+		data = APIC_BUS_FREQUENCY;
+		break;
+	default:
+		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
+		return 1;
+	}
+	*pdata = data;
+	return 0;
+}
+
+int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
+{
+	if (kvm_hv_msr_partition_wide(msr)) {
+		int r;
+
+		mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
+		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
+		mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
+		return r;
+	} else
+		return kvm_hv_set_msr(vcpu, msr, data, host);
+}
+
+int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
+{
+	if (kvm_hv_msr_partition_wide(msr)) {
+		int r;
+
+		mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
+		r = kvm_hv_get_msr_pw(vcpu, msr, pdata);
+		mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
+		return r;
+	} else
+		return kvm_hv_get_msr(vcpu, msr, pdata, host);
+}
+
+static __always_inline int get_sparse_bank_no(u64 valid_bank_mask, int bank_no)
+{
+	int i = 0, j;
+
+	if (!(valid_bank_mask & BIT_ULL(bank_no)))
+		return -1;
+
+	for (j = 0; j < bank_no; j++)
+		if (valid_bank_mask & BIT_ULL(j))
+			i++;
+
+	return i;
+}
+
+static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
+			    u16 rep_cnt, bool ex)
+{
+	struct kvm *kvm = current_vcpu->kvm;
+	struct kvm_vcpu_hv *hv_current = &current_vcpu->arch.hyperv;
+	struct hv_tlb_flush_ex flush_ex;
+	struct hv_tlb_flush flush;
+	struct kvm_vcpu *vcpu;
+	unsigned long vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)] = {0};
+	unsigned long valid_bank_mask = 0;
+	u64 sparse_banks[64];
+	int sparse_banks_len, i;
+	bool all_cpus;
+
+	if (!ex) {
+		if (unlikely(kvm_read_guest(kvm, ingpa, &flush, sizeof(flush))))
+			return HV_STATUS_INVALID_HYPERCALL_INPUT;
+
+		trace_kvm_hv_flush_tlb(flush.processor_mask,
+				       flush.address_space, flush.flags);
+
+		sparse_banks[0] = flush.processor_mask;
+
+		/*
+		 * Work around possible WS2012 bug: it sends hypercalls
+		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
+		 * while also expecting us to flush something and crashing if
+		 * we don't. Let's treat processor_mask == 0 same as
+		 * HV_FLUSH_ALL_PROCESSORS.
+		 */
+		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
+			flush.processor_mask == 0;
+	} else {
+		if (unlikely(kvm_read_guest(kvm, ingpa, &flush_ex,
+					    sizeof(flush_ex))))
+			return HV_STATUS_INVALID_HYPERCALL_INPUT;
+
+		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
+					  flush_ex.hv_vp_set.format,
+					  flush_ex.address_space,
+					  flush_ex.flags);
+
+		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
+		all_cpus = flush_ex.hv_vp_set.format !=
+			HV_GENERIC_SET_SPARSE_4K;
+
+		sparse_banks_len = bitmap_weight(&valid_bank_mask, 64) *
+			sizeof(sparse_banks[0]);
+
+		if (!sparse_banks_len && !all_cpus)
+			goto ret_success;
+
+		if (!all_cpus &&
+		    kvm_read_guest(kvm,
+				   ingpa + offsetof(struct hv_tlb_flush_ex,
+						    hv_vp_set.bank_contents),
+				   sparse_banks,
+				   sparse_banks_len))
+			return HV_STATUS_INVALID_HYPERCALL_INPUT;
+	}
+
+	cpumask_clear(&hv_current->tlb_lush);
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
+		int bank = hv->vp_index / 64, sbank = 0;
+
+		if (!all_cpus) {
+			/* Banks >64 can't be represented */
+			if (bank >= 64)
+				continue;
+
+			/* Non-ex hypercalls can only address first 64 vCPUs */
+			if (!ex && bank)
+				continue;
+
+			if (ex) {
+				/*
+				 * Check is the bank of this vCPU is in sparse
+				 * set and get the sparse bank number.
+				 */
+				sbank = get_sparse_bank_no(valid_bank_mask,
+							   bank);
+
+				if (sbank < 0)
+					continue;
+			}
+
+			if (!(sparse_banks[sbank] & BIT_ULL(hv->vp_index % 64)))
+				continue;
+		}
+
+		/*
+		 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we
+		 * can't analyze it here, flush TLB regardless of the specified
+		 * address space.
+		 */
+		__set_bit(i, vcpu_bitmap);
+	}
+
+	kvm_make_vcpus_request_mask(kvm,
+				    KVM_REQ_TLB_FLUSH | KVM_REQUEST_NO_WAKEUP,
+				    vcpu_bitmap, &hv_current->tlb_lush);
+
+ret_success:
+	/* We always do full TLB flush, set rep_done = rep_cnt. */
+	return (u64)HV_STATUS_SUCCESS |
+		((u64)rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
+}
+
+bool kvm_hv_hypercall_enabled(struct kvm *kvm)
+{
+	return READ_ONCE(kvm->arch.hyperv.hv_hypercall) & HV_X64_MSR_HYPERCALL_ENABLE;
+}
+
+static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
+{
+	bool longmode;
+
+	longmode = is_64_bit_mode(vcpu);
+	if (longmode)
+		kvm_register_write(vcpu, VCPU_REGS_RAX, result);
+	else {
+		kvm_register_write(vcpu, VCPU_REGS_RDX, result >> 32);
+		kvm_register_write(vcpu, VCPU_REGS_RAX, result & 0xffffffff);
+	}
+}
+
+static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
+{
+	kvm_hv_hypercall_set_result(vcpu, result);
+	++vcpu->stat.hypercalls;
+	return kvm_skip_emulated_instruction(vcpu);
+}
+
+static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
+{
+	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
+}
+
+static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
+{
+	struct eventfd_ctx *eventfd;
+
+	if (unlikely(!fast)) {
+		int ret;
+		gpa_t gpa = param;
+
+		if ((gpa & (__alignof__(param) - 1)) ||
+		    offset_in_page(gpa) + sizeof(param) > PAGE_SIZE)
+			return HV_STATUS_INVALID_ALIGNMENT;
+
+		ret = kvm_vcpu_read_guest(vcpu, gpa, &param, sizeof(param));
+		if (ret < 0)
+			return HV_STATUS_INVALID_ALIGNMENT;
+	}
+
+	/*
+	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
+	 * have no use for it, and in all known usecases it is zero, so just
+	 * report lookup failure if it isn't.
+	 */
+	if (param & 0xffff00000000ULL)
+		return HV_STATUS_INVALID_PORT_ID;
+	/* remaining bits are reserved-zero */
+	if (param & ~KVM_HYPERV_CONN_ID_MASK)
+		return HV_STATUS_INVALID_HYPERCALL_INPUT;
+
+	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
+	rcu_read_lock();
+	eventfd = idr_find(&vcpu->kvm->arch.hyperv.conn_to_evt, param);
+	rcu_read_unlock();
+	if (!eventfd)
+		return HV_STATUS_INVALID_PORT_ID;
+
+	eventfd_signal(eventfd, 1);
+	return HV_STATUS_SUCCESS;
+}
+
+int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
+{
+	u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
+	uint16_t code, rep_idx, rep_cnt;
+	bool fast, longmode, rep;
+
+	/*
+	 * hypercall generates UD from non zero cpl and real mode
+	 * per HYPER-V spec
+	 */
+	if (kvm_x86_ops->get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
+		kvm_queue_exception(vcpu, UD_VECTOR);
+		return 1;
+	}
+
+	longmode = is_64_bit_mode(vcpu);
+
+	if (!longmode) {
+		param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
+			(kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff);
+		ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
+			(kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
+		outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
+			(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
+	}
+#ifdef CONFIG_X86_64
+	else {
+		param = kvm_register_read(vcpu, VCPU_REGS_RCX);
+		ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
+		outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
+	}
+#endif
+
+	code = param & 0xffff;
+	fast = !!(param & HV_HYPERCALL_FAST_BIT);
+	rep_cnt = (param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
+	rep_idx = (param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
+	rep = !!(rep_cnt || rep_idx);
+
+	trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
+
+	switch (code) {
+	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
+		if (unlikely(rep)) {
+			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+			break;
+		}
+		kvm_vcpu_on_spin(vcpu, true);
+		break;
+	case HVCALL_SIGNAL_EVENT:
+		if (unlikely(rep)) {
+			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+			break;
+		}
+		ret = kvm_hvcall_signal_event(vcpu, fast, ingpa);
+		if (ret != HV_STATUS_INVALID_PORT_ID)
+			break;
+		/* maybe userspace knows this conn_id: fall through */
+	case HVCALL_POST_MESSAGE:
+		/* don't bother userspace if it has no way to handle it */
+		if (unlikely(rep || !vcpu_to_synic(vcpu)->active)) {
+			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+			break;
+		}
+		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
+		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
+		vcpu->run->hyperv.u.hcall.input = param;
+		vcpu->run->hyperv.u.hcall.params[0] = ingpa;
+		vcpu->run->hyperv.u.hcall.params[1] = outgpa;
+		vcpu->arch.complete_userspace_io =
+				kvm_hv_hypercall_complete_userspace;
+		return 0;
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
+		if (unlikely(fast || !rep_cnt || rep_idx)) {
+			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+			break;
+		}
+		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
+		break;
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
+		if (unlikely(fast || rep)) {
+			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+			break;
+		}
+		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
+		break;
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
+		if (unlikely(fast || !rep_cnt || rep_idx)) {
+			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+			break;
+		}
+		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
+		break;
+	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
+		if (unlikely(fast || rep)) {
+			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+			break;
+		}
+		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
+		break;
+	default:
+		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
+		break;
+	}
+
+	return kvm_hv_hypercall_complete(vcpu, ret);
+}
+
+void kvm_hv_init_vm(struct kvm *kvm)
+{
+	mutex_init(&kvm->arch.hyperv.hv_lock);
+	idr_init(&kvm->arch.hyperv.conn_to_evt);
+}
+
+void kvm_hv_destroy_vm(struct kvm *kvm)
+{
+	struct eventfd_ctx *eventfd;
+	int i;
+
+	idr_for_each_entry(&kvm->arch.hyperv.conn_to_evt, eventfd, i)
+		eventfd_ctx_put(eventfd);
+	idr_destroy(&kvm->arch.hyperv.conn_to_evt);
+}
+
+static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
+{
+	struct kvm_hv *hv = &kvm->arch.hyperv;
+	struct eventfd_ctx *eventfd;
+	int ret;
+
+	eventfd = eventfd_ctx_fdget(fd);
+	if (IS_ERR(eventfd))
+		return PTR_ERR(eventfd);
+
+	mutex_lock(&hv->hv_lock);
+	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
+			GFP_KERNEL);
+	mutex_unlock(&hv->hv_lock);
+
+	if (ret >= 0)
+		return 0;
+
+	if (ret == -ENOSPC)
+		ret = -EEXIST;
+	eventfd_ctx_put(eventfd);
+	return ret;
+}
+
+static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
+{
+	struct kvm_hv *hv = &kvm->arch.hyperv;
+	struct eventfd_ctx *eventfd;
+
+	mutex_lock(&hv->hv_lock);
+	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
+	mutex_unlock(&hv->hv_lock);
+
+	if (!eventfd)
+		return -ENOENT;
+
+	synchronize_srcu(&kvm->srcu);
+	eventfd_ctx_put(eventfd);
+	return 0;
+}
+
+int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
+{
+	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
+	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
+		return -EINVAL;
+
+	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
+		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
+	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
+}